I use the optical connection to my surround system, and turn the TV off.

Same here. I start Pandora, turn off the TV. However, I've found that the Tivo Pandora feed stops after a few hours. Then of course, you have to turn the TV back on, and restart it. I really wish the Tivo Android App allowed you to start and manage Pandora.

This is an option on other platforms. With my Sony internet connected TV the Pandora application has the option of screen saver with album art or a black screen. This is one of the reasons I use it instead of the Tivo application. Not much hope Tivo will ever update the program.